Common functions of the chloroplast and mitochondrial co-chaperones cpDnaJL (CDF1) and mtDnaJ (PAM16) in protein import and ROS scavenging in Arabidopsis thaliana

Gray, John C.; Rustgi, Sachin; Wettstein, Diter von; Reinbothe, Christiane; Reinbothe, Steffen

doi:10.1080/19420889.2015.1119343

Cited by 11 publications

(5 citation statements)

References 31 publications

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“…Although the absolute expression levels of these three genes differ, their comparative expression is largely parallel and no more than 3.8-fold different at most (Supplementary Figures S15E,F). We had previously reported that CDF1 is another component operating in the Pchlide-dependent plastid import pathway of pPORA, (Lee et al, 2013; Reinbothe et al, 2015; Gray et al, 2016). Similar to PTC52 knock-out mutants, CDF1 T-DNA insertion mutants were embryo-lethal (Lee et al, 2013; Reinbothe et al, 2015) and DEX-induced RNA interference of CDF1 caused the same porphyrin-sensitized cell death phenotype as observed here for RNAi seedlings deprived of PTC52.…”

Section: Discussionmentioning

confidence: 99%

A Protochlorophyllide (Pchlide) a Oxygenase for Plant Viability

et al. 2019

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Higher plants contain a small, 5-member family of Rieske non-heme oxygenases that comprise the inner plastid envelope protein TIC55, phaeophorbide a oxygenasee (PAO), chlorophyllide a oxygenase (CAO), choline monooxygenase, and a 52 kDa protein (PTC52) associated with the precursor NADPH:protochlorophyllide (Pchlide) oxidoreductase A (pPORA) A translocon (PTC). Some of these chloroplast proteins have documented roles in chlorophyll biosynthesis (CAO) and degradation (PAO and TIC55), whereas the function of PTC52 remains unresolved. Biochemical evidence provided here identifies PTC52 as Pchlide a oxygenase of the inner plastid envelope linking Pchlide b synthesis to pPORA import. Protochlorophyllide b is the preferred substrate of PORA and its lack no longer allows pPORA import. The Pchlide b -dependent import pathway of pPORA thus operates in etiolated seedlings and is switched off during greening. Using dexamethasone-induced RNA interference (RNAi) we tested if PTC52 is involved in controlling both, pPORA import and Pchlide homeostasis in planta . As shown here, RNAi plants deprived of PTC52 transcript and PTC52 protein were unable to import pPORA and died as a result of excess Pchlide a accumulation causing singlet oxygen formation during greening. In genetic studies, no homozygous ptc52 knock-out mutants could be obtained presumably as a result of embryo lethality, suggesting a role for PTC52 in the initial greening of plant embryos. Phylogenetic studies identified PTC52-like genes amongst unicellular photosynthetic bacteria and higher plants, suggesting that the biochemical function associated with PTC52 may have an ancient evolutionary origin. PTC52 also harbors conserved motifs with bacterial oxygenases such as the terminal oxygenase component of 3-ketosteroid 9-alpha-hydroxylase (KshA) from Rhodococcus rhodochrous . 3D-modeling of PTC52 structure permitted the prediction of amino acid residues that contribute to the substrate specificity of this enzyme. In vitro -mutagenesis was used to test the predicted PTC52 model and provide insights into the reaction mechanism of this Rieske non-heme oxygenase.

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Section: Discussionmentioning

confidence: 99%

A Protochlorophyllide (Pchlide) a Oxygenase for Plant Viability

et al. 2019

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“…In rnpm2, which does not contain NLRs, a gene orthologous to AtPAM16 showed no expression in the resistant genotype and high expression in the susceptible genotype. PAM16 is known to play a role in plant immunity, as shown in A. thaliana mutants lacking this gene, which exhibit enhanced disease resistance [74,75]. Backcrossing studies with an AtPam16 knockout mutant (muse5-1) indicated that the recessive inheritance of the resistant phenotype aligns with the recessive inheritance pattern observed for rnpm2.…”

Section: Functional Enrichment In the Resistant Genotype Suggest Anti...mentioning

confidence: 93%

Transcriptome analysis of resistant and susceptible M. truncatula genotypes in response to the necrotrophic fungus A. medicaginicola

Botkin,

Curtin

2024

Preprint

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Ascochyta blights cause yield losses in all major legume crops. Spring black stem (SBS) and leaf spot disease is a major foliar disease of Medicago truncatula and M. sativa (alfalfa) caused by the necrotrophic fungus Ascochyta medicaginicola. This present study sought to identify candidate genes for SBS disease resistance for future functional validation. We employed RNA-seq to profile the transcriptomes of a resistant (HM078) and susceptible (A17) genotype of M. truncatula at 24, 48, and 72 hours post inoculation. Preliminary microscopic examination showed reduced pathogen growth on the resistant genotype. In total, 192 and 2,908 differentially expressed genes (DEGs) were observed in the resistant and susceptible genotype, respectively. Functional enrichment analysis revealed the susceptible genotype engaged in processes in the cell periphery and plasma membrane, as well as flavonoid biosynthesis whereas the resistant genotype utilized calcium ion binding, cell wall modifications, and external encapsulating structures. Candidate genes for disease resistance were selected based on criteria, among the top ten upregulated genes in the resistant genotype, upregulated over time in the resistant genotype, hormone pathway genes, plant disease resistance genes, receptor-like kinases, contrasting expression profiles in QTL for disease resistance, and upregulated genes in enriched pathways. Overall, 19 candidate genes for SBS disease resistance were identified with support from the literature. These genes will be sources for future targeted mutagenesis and candidate gene validation potentially helping to improve disease resistance to this devastating foliar pathogen.

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“…Recent studies have reported that molecular chaperones are essential for the translocation of proteins from one cellular compartment to another. For example, mitochondria and chloroplasts import over 95% of their protein constituents from the cytosol, which is further transported into a particular cell organelle via a specific protein import machinery called ATP-driven HSP70 (cpHSP70) [37]. In another study, Sin et al reported that sHSP20 (small heat shock protein 20) is essential for the nuclear translocation of PKD1 (protein kinase D1) [38].…”

Section: Grp170mentioning

confidence: 99%

The Interplay between Heat Shock Proteins and Cancer Pathogenesis: A Novel Strategy for Cancer Therapeutics

Somu,

Mohanty,

Basavegowda

et al. 2024

Cancers

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Heat shock proteins (HSPs) are developmentally conserved families of protein found in both prokaryotic and eukaryotic organisms. HSPs are engaged in a diverse range of physiological processes, including molecular chaperone activity to assist the initial protein folding or promote the unfolding and refolding of misfolded intermediates to acquire the normal or native conformation and its translocation and prevent protein aggregation as well as in immunity, apoptosis, and autophagy. These molecular chaperonins are classified into various families according to their molecular size or weight, encompassing small HSPs (e.g., HSP10 and HSP27), HSP40, HSP60, HSP70, HSP90, and the category of large HSPs that include HSP100 and ClpB proteins. The overexpression of HSPs is induced to counteract cell stress at elevated levels in a variety of solid tumors, including anticancer chemotherapy, and is closely related to a worse prognosis and therapeutic resistance to cancer cells. HSPs are also involved in anti-apoptotic properties and are associated with processes of cancer progression and development, such as metastasis, invasion, and cell proliferation. This review outlines the previously mentioned HSPs and their significant involvement in diverse mechanisms of tumor advancement and metastasis, as well as their contribution to identifying potential targets for therapeutic interventions.

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Common functions of the chloroplast and mitochondrial co-chaperones cpDnaJL (CDF1) and mtDnaJ (PAM16) in protein import and ROS scavenging in Arabidopsis thaliana

Cited by 11 publications

References 31 publications

A Protochlorophyllide (Pchlide) a Oxygenase for Plant Viability

A Protochlorophyllide (Pchlide) a Oxygenase for Plant Viability

Transcriptome analysis of resistant and susceptible M. truncatula genotypes in response to the necrotrophic fungus A. medicaginicola

The Interplay between Heat Shock Proteins and Cancer Pathogenesis: A Novel Strategy for Cancer Therapeutics

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